2 Answers
2

This isn't a particularly useful answer. Putting his two WD 1TB drives onto a hardware RAID controller isn't likely to improve performance substantively, if at all. He needs a much better disk IO system to handle this load.
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Daniel LawsonAug 19 '10 at 1:28

What does the server do? Web server? Database server? File Server? What could be sources of load?

Has load increased? Has anything changed?

What do you have RAIDed? Looks like SCSI disks. 15k RPM?

Is the RAID1 your boot volume? USed for swap? etc

Without specifics it's tough to give advice, however I can state from experience that I had a RAID1 array which was a huge bottleneck on web/database server -- upgrading to RAID10 relieved the bottleneck. But I can't say for certain that this is your issue as well without more info.

EDIT: Based on your response that this is a cPanel server and the boot volume is RAIDed, you experience does sound similar to mine. I had a cPanel server with a few hunderd accounts and two SATA drives in a RAID1; I saw high load because multiple requests writing to those drives killed performance. RAID10 did the trick for me.

What does the server do? Web server? Database server? File Server? The server its a cPanel runing apache, mysql, exim, dovecot, pure-ftpd with 600 accounts. What could be sources of load? The Raid?! Has load increased? Has anything changed? Nothing What do you have RAIDed? Looks like SCSI disks. 15k RPM? WD 1TB 7200 Is the RAID1 your boot volume? Yes, all the partition are in raid1 /boot is /dev/md0 USed for swap? swap is in raid1 too, but never the system touch him
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melocotonApr 20 '10 at 11:12

@melocoton: This would be easier to read if you edited your question and put it in there.
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JoshApr 20 '10 at 13:27

@melocoton: Nevermind, I see that you did put it in the question. See my updated answer; consider RAID10.
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JoshApr 20 '10 at 13:31